It has always been difficult to sell a significant number of books, self or trad publishing...and it always will be. Just as it is difficult for people to build careers as actors, musicians, etc. But this comparison is constantly misrepresented.
You cannot compare trade published authors one for one with self-published ones. Probably one in one thousand prospective trade published authors ever get a contract, while that whole 1,000 can self-publish. If you want to compare accurately, you would need to take the entire pool of people who have submitted to a trade publisher, whether they were accepted or rejected and then compare this to the pool of self-published authors. That is the accurate comparison, and, if the numbers were available, I don't think it would support trade publishing. If you take a trade published author who sells 10,000 books and average them with 1,000 who died in the slush pile, your average in the trade published group sold 10 books. Those are the kinds of numbers they like to show for self-pubbed authors.
An "emerging" author is someone who has to get a trade deal to even get published, and the vast majority of them won't. It's great for trade publishers to scoop off only the ones they accept and compare them to everyone in the world who put a few hours into throwing a book up on Amazon. I'd like to see a real comparison of apples vs. apples.